From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D07F4C433F5 for ; Tue, 30 Nov 2021 13:10:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3C97F6B0073; Tue, 30 Nov 2021 08:09:55 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 378D66B0074; Tue, 30 Nov 2021 08:09:55 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 268C06B0075; Tue, 30 Nov 2021 08:09:55 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0198.hostedemail.com [216.40.44.198]) by kanga.kvack.org (Postfix) with ESMTP id 19B126B0073 for ; Tue, 30 Nov 2021 08:09:55 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D22A2182067A6 for ; Tue, 30 Nov 2021 13:09:44 +0000 (UTC) X-FDA: 78865628646.11.3D238EB Received: from outbound-smtp08.blacknight.com (outbound-smtp08.blacknight.com [46.22.139.13]) by imf16.hostedemail.com (Postfix) with ESMTP id 65680F00008C for ; Tue, 30 Nov 2021 13:09:38 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp08.blacknight.com (Postfix) with ESMTPS id 55AFE1C3482 for ; Tue, 30 Nov 2021 13:09:38 +0000 (GMT) Received: (qmail 27593 invoked from network); 30 Nov 2021 13:09:38 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.29]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 30 Nov 2021 13:09:38 -0000 Date: Tue, 30 Nov 2021 13:09:35 +0000 From: Mel Gorman To: Mike Galbraith Cc: Alexey Avramov , Andrew Morton , Michal Hocko , Vlastimil Babka , Rik van Riel , Darrick Wong , regressions@lists.linux.dev, Linux-fsdevel , Linux-MM , LKML Subject: Re: [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to make progress Message-ID: <20211130130935.GR3366@techsingularity.net> References: <20211125151853.8540-1-mgorman@techsingularity.net> <20211127011246.7a8ac7b8@mail.inbox.lv> <20211129150117.GO3366@techsingularity.net> <20211130112244.GQ3366@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 65680F00008C Authentication-Results: imf16.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf16.hostedemail.com: domain of mgorman@techsingularity.net designates 46.22.139.13 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net X-Stat-Signature: y4dyq88dxpctmo58k8f3zf3akigw6ro4 X-HE-Tag: 1638277778-959195 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Nov 30, 2021 at 01:51:10PM +0100, Mike Galbraith wrote: > On Tue, 2021-11-30 at 13:00 +0100, Mike Galbraith wrote: > > On Tue, 2021-11-30 at 11:22 +0000, Mel Gorman wrote: > > > On Tue, Nov 30, 2021 at 11:14:32AM +0100, Mike Galbraith wrote: > > > > > =A0=A0=A0=A0=A0=A0} > > > > > +=A0=A0=A0=A0=A0=A0=A0if (2 * write_pending <=3D reclaimable) > > > > > > > > That is always true here... > > > > > > > > > > Always true for you or always true in general? > > > > "Here" as in the boxen located at my GPS coordinates :) > > > > > The intent of the check is "are a majority of reclaimable pages > > > marked WRITE_PENDING?". It's similar to the check that existed prio= r > > > to 132b0d21d21f ("mm/page_alloc: remove the throttling logic from t= he > > > page allocator"). > > > > I'll put my trace_printk() back and see if I can't bend-adjust it. >=20 > As it sits, write_pending is always 0 with tail /dev/zero. >=20 That is not a surprise for the test in question as it doesn't trigger a case where there are lots of page cache being marked dirty and write pending. --=20 Mel Gorman SUSE Labs